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    SubjectRe: [RFC PATCH V2 0/6] perf: Intel uncore pmu counting support
    On 04/23/2012 11:21 PM, Stephane Eranian wrote:
    > Hi,
    >
    > [+jolsa as it may have something to do with the event parser]
    >
    > I started testing this on my NHM desktop machine, and I ran into the following
    > problem:
    > $ perf stat -a -C 0 -e uncore_nhm/CLOCKTICKS/,cycles,ref-cycles --
    > taskset -c 0 noploop 1
    > noploop for 1 seconds
    > Performance counter stats for 'taskset -c 0 noploop 1':
    > 3,435,695,848 cycles # 0.000 GHz
    > [100.00%]
    > 2,803,309,845 ref-cycles
    > 2,410,926,590 pmu
    > 1.001391268 seconds time elapsed
    >
    > First here, the cmdline event order is not respected. uncore events
    > appear at the end. That's not very
    > intuitive. Especially when you know that they all show up as 'pmu'. In
    > other words, you cannot figure
    > out what each value represents.
    >
    > $ sudo perf stat -a -C 0 -e uncore_nhm/CLOCKTICKS/ -- taskset -c 0 noploop 1
    > noploop for 1 seconds
    > Performance counter stats for 'taskset -c 0 noploop 1':
    > 2,410,862,301 pmu
    > 1.001393218 seconds time elapsed
    >
    > That looks like the right value, well, minus the 'pmu' event name. But
    > that's a different problem.
    >
    > But then, the pathological case:
    >
    > $ sudo perf stat -a -C 0 -e
    > uncore_nhm/CLOCKTICKS/,uncore_nhm/QMC_NORMAL_READS_ANY/ -- taskset -c
    > 0 noploop 1
    > noploop for 1 seconds
    > Performance counter stats for 'taskset -c 0 noploop 1':
    > 10,705 pmu
    > 1.001395772 seconds time elapsed
    >
    > If you pass more than one uncore event, all but the last one are
    > suppressed from the output.
    > It does not happen with core PMU events.
    >
    > Looks like something may be wrong in the way the parser adds uncore events.
    >
    >
    Thank you very much for pointing out this. I will try changing the flex and
    bison input files to generate reentrant parser. I hope it can solve all these
    issues.

    Regards
    Yan, Zheng

    > On Sun, Apr 1, 2012 at 3:41 AM, Yan, Zheng <zheng.z.yan@intel.com> wrote:
    >> Hi, all
    >>
    >> Here is the RFC patches to add uncore counting support for Nehalem,
    >> Sandy Bridge and Sandy Bridge-EP, applied on top of current tip.
    >> The code is based on Lin Ming's old patches.
    >>
    >> For Nehalem and Sandy Bridge-EP, A few general events are exported
    >> under directory:
    >> /sys/bus/event_source/devices/uncore_xxx/events/
    >>
    >> You can use 'perf stat' to access to the uncore pmu. For example:
    >> perf stat -a -C 0 -e 'uncore_nhm/QMC_WRITES_FULL_ANY/' sleep 1
    >>
    >> Any comment is appreciated.
    >> Thank you
    >>
    >> ---
    >> Changes since v1:
    >> - Modify perf tool to parse events from sysfs
    >> - A few minor code cleanup
    >>



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